polishing roll



STATES Patented Aug. 20, 1940 140F E E Application March 15, 1940, Serial no. 324,122

3 Claims.

' The invention relates to rotary cylinders, to the surfaceof which, sheet abrasives such as sandpaper, may be applied for grinding and pol- 'ishing purposes.

' 'The prime object of the invention is to provide such a cylinder (or roll), composed of few partsj wh'ich can be cheaply formed and assembled, and which shall present novel and improved means for stretching the abrasive covering over the surface of the roll, and for holding it securely in place.

Another object is to accomplish these results without the use of any wedge, cleat or other extraneous or loosely attached part, and without the use of any clamping device other than a single nut, located at the end of the roll.

Another object is to provide a roll having its exterior surface entirely free from gaps, ridges and depressions, and with one of its ends free from all protruding parts, so that it will yield a maximum amount of service from the abrasive, and work effectively on the inner surfaces of angular objects.

Another object is to provide a roll which shall be equally adaptable for use with all commercially available sheet abrasives, without their being especially formed or processed for roll coverings.

With these and other objects in view, the invention consists essentially of a hollow cylinder, composed of two similar interlocking semicylindrical segments, opposedly mounted on a common tubular shaft. The segments have divergent edges forming slots in the surface of the cylinder, and a. certain degree of relative motion, by means of which the slots may be opened and closed.

One of the segments is mounted rigidly upon the shaft and the other is retained in position by means of a nut, threadedly mounted on the shaft at the outer end of the second segment. This second segment is free to move both laterally and rotatably upon the shaft, within limits defined by its proximity to the first segment and the retaining nut upon the shaft.

The ensemble constitutes a unit which may be mounted on any suitable spindle, and upon which an abrasive covering may be stretched and held by inserting its ends in one of the slots, and tightening the retaining nut.

Such a unit is shown in the accompanying drawing, in which Figure 1 is an end view of the roll showing the position in which the ends of the abrasive are held in one of the slots in the surface of the roll.

The method of applying force for'stretching the abrasive and securing it in place will appear in the detailed description to follow. It-should be noted also that this force-is app1ied ;without effecting any change,- either in thediameter or in the circularity ofthe cylinder. 0 l l a Figure 2 is a longitudinal sectionthrough the roll on the line--A-B of Figure '1. i 1;;

Figure 3 is a perspective view of one of the two similar segments composing the roll. The winding appearance of one of the edges of the segment should be associated, in thought, with:

Figure 4, a diagram of the developed surface of the cylinder, showing the divergent edges of the interlocking segments, and their sliding action in closing the slot which holds the abrasive.

Referring to the drawing in detail, in which similar designating numerals refer to the same parts throughout the series; the two segments 24 and 5, composing the roll, are similar in form, the details of which are best shown in Figure 3. The shell 24, has radially faced edges H and I2, one of which II is straight and parallel to the axis of the roll. The other edge I2, is uniformly helical in form, subtending an arc of considerable proportions on the circumference of the roll.

Brackets 9 and ID are formed on the inner surface of the shell 24, and bearings 'l and 8 are formed in these brackets for supporting the entire segment on a central shaft. In like manner, corresponding brackets 21 and 22, Figure 2, support the complementary segment 5, on the same shaft, the brackets being so disposed as to alternate wtih each other and to allow some relative motion between the segments.

When thus loosely mounted in opposed relation on a common shaft, the segments form a complete cylinder, having slots in its surface, one of which is straight, while the other and opposite one is spiral in form.

By means of the tight fitting boss I5, formed on the bracket ill, the entire segment 24 is rigidly fixed to the tubular shaft 6. The bracket 2! of segment 5, is formed at some distance from the end of the segment, and is flanked by the abrasive 23, in place on the surface of the roll.

The clamping action is illustrated in the diagram, Figure 4, in which the surfaces of the segments 24 and 5 are conventionalized. It is manifest that, with the sliding member 5 bearing against the fixed member .24, when pressure is brought to bear in the direction indicated by the arrows cd--e, the sliding member 5, will be forced to assume the direction indicated by the arrow f, closing the slot H.

A bushing 20, may be used for adapting the roll for use on any available spindle regardless of size, and the set-screw 19 serves for holding it in place thereon. H

' One variation which may be made to meet the requirements of some classes of work is, that the slot designated as straight in the foregoing description, may itself be of a somewhat spiral form, provided it shall differ either in degree or;

in direction from its opposing slot, I

Qther changes in detail may be made without departing from the spirit or scope of this invention, but, what I claim as new is: I I

1. In a polishing roll, a cylinder comprising a central tubular shaft, a plurality of interlocking segments having divergent'edges, mounted thereon, bearings alternately disposed on the shaft supporting the segments, slots in the surshaft, relative motion between the segments,

bearings formed on brackets within the segments forsupporting them on the shaft, the outer bearing of one segment formed at a distance from the end of the cylinder, so that its retaining nut and the shaft on which it is .mounted will not project beyond the end of the cylinder, substantially as described.

3. In a polishing roll, a cylinder comprising a plurality of segments mounted on a common shaft, relative motion between the segments,

"means for holding the segments in Variable proximity to each other, the adjacent edges of the segments forming spiral slots in the surface of the cylinder, the slots varying in degree and direction one from another substantially as described.

' FRED F. BILLINGS. 

